In certain applications, the presence of a gas entrained in a liquid can be undesirable or cause problems. For example, in microgravity, gas bubbles must be removed from drinking water. Additionally, high gas content in a liquid that is pumped can result in vapor lock or pump cavitation. Gas present in a liquid that is delivered through microchannels can clog the channels and have other negative impacts. To reduce the potential problems caused by the presence of a gas within a liquid, the gas is removed from the liquid. In microgravity environments, gas removal from a liquid is difficult.
Techniques for removing gases from liquids in microgravity environments include centrifugal separation, membrane systems, condensation systems and capillary methods. A centrifugal separator spins fluid via a spinning housing to create a buoyancy force that separates the gas from the liquid. In membrane systems, gas is able to migrate across a membrane while the liquid cannot (e.g., a hydrophobic membrane where the liquid is water). Condensation systems cause water to condense out of air as the air comes into contact with cold surfaces. In capillary methods, liquid is allowed to exit a vessel as a result of capillary action. While each of these methods may be suitable for removing gases from liquids in some situations, the necessary components can be heavy, expensive to operate or maintain, or complicated.